April 8, 2009 - Peering through Nature's telescope - Gravitational
Lensing as a window into the distant universe - Mr. Karoun Thanjavur,
Graduate Student, Dep't of Astronomy and Physics, University of Victoria
Abstract: Gravitational "bending" of light is one of the many
unintuitive phenomena predicted by Einstein's theory of Relativistic Gravity,
which have since been unambiguously borne out by observations. Since the first
confirmation of a gravitational lens in 1979 -nearly 45 years after it was
proposed- the catalogue of confirmed lenses now runs to a few hundreds. With
advances in the instrumentation available at the modern 8m class telescopes, the
magnification boost provided by this Nature's telescope is now being harnessed
to probe physical processes in the high red-shift universe with a level of
detail that would otherwise be extremely challenging. My presentation aims to
pictorially describe gravitational lensing, trace its history as an
observational tool and present two applications and related results drawn from
my own thesis research.
Bio: Developing innovative uses for
gravitational lensing as an observational tool was the focus of my recently
completed dissertation entitled Cosmic Applications of Gravitational Lens
Assisted Spectroscopy (GLAS) (UVic, Oct. 08), For this work, I use integral
field and multi-object spectroscopy of gravitational lenses to understand
processes governing star formation and associated feedback mechanisms in
galaxies at red-shift beyond one as well as to map the assembly of mass on the
scale of galaxy groups. These explorations of the distant universe come after a
full career as a mechanical engineer, specializing in control systems and
robotics, and so this opportunity to combine cutting-edge telescope technology
with one of Nature's many wonders has been an enriching experience. During the
current academic semester, I am teaching General Relativity and Cosmology at
UVic, which is providing me with an additional opportunity to share these
fascinating areas with my group of senior students.
